Spatiotemporal Dynamics and Driving Factors of Urban Expansion in the Chongqing Metropolitan Area Based on Nighttime Light Remote Sensing

This study investigated the spatiotemporal dynamics and driving mechanisms of urban expansion in the Chongqing Metropolitan Area by integrating multi-source big data and employing a suite of quantitative analytical methods. Drawing upon high-resolution remote sensing imagery, land-use datasets, socioeconomic statistics, and transportation network data spanning 2019 to 2023, the research revealed pronounced spatial and temporal heterogeneity in urban growth. Specifically, expansion manifested through a core-periphery spatial structure and temporal imbalances. The findings underscore a growing economic interconnectedness between core urban districts and peripheral cities such as Guang’an and Luzhou, giving rise to a multilayered and increasingly networked spatial-economic system. Moreover, urban expansion is shown to be tightly coupled with industrial distribution, transportation optimization, and regional integration strategies. In particular, the implementation of the Chengdu-Chongqing Twin-City Economic Circle has significantly facilitated cross-regional factor mobility and spatial restructuring, thereby accelerating coordinated development across the metropolitan area. Looking forward, urban expansion in the Chongqing Metropolitan Region is expected to continue leveraging transportation infrastructure and strategic industrial placement to advance regional economic integration.